Dyes for keratin fibres containing 1,3-diamino-4-heteroarylbenzene derivatives and novel 1,3-diamino-4-heteroarylbenzene derivatives

ABSTRACT

Colorants for keratin fibers containing 1,3-diamino-4-heteroarylbenzene derivatives of general formula (I) or the physiologically tolerated salts thereof                    
     as well as novel 1,3-diamino-4-heteroarylbenzene derivatives.

The invention relates to agents for oxidative dyeing of keratin fibers,particularly human hair, based on a developer/coupler combinationcontaining as the coupler a 1,3-diamino-4-heteroarylbenzene derivative,as well as to novel 1,3-diamino-4-heteroarylbenzene derivatives.

In the area of keratin fiber dyeing, particularly hair dyeing, oxidationdyes have attained substantial importance. In this case, the colorationis produced by reaction of certain developers with certain couplers inthe presence of an appropriate oxidant. Suitable developers are, inparticular, 2,5-diaminotoluene, 2,5-diaminophenylethyl alcohol,p-aminophenol, 1,4-diaminobenzene and4,5-diamino-1-(2′-hydroxyethyl)pyrazole and suitable couplers are, forexample, resorcinol, 2-aminoresorcinol, 1-naphthol, 3-aminophenol,m-phenylenediamine, 2-amino-4-(2′-hydroxyethyl)aminoanisole,1,3-diamino-4-(2′-hydroxyethoxy)benzene and 2,4-diamino-5-fluorotoluene.

The oxidation dyes used for dyeing human hair must meet numerousrequirements in addition to that of being able to produce colorations ofthe desired intensity. For example, these dyes must be harmless from atoxicological and dermatological standpoint, and the hair colorationsobtained must have good light fastness, resistance to permanent waving,acid fastness and rubbing fastness. In any case, however, in the absenceof exposure to light, rubbing and chemicals such colorations must remainstable over a period of at least 4 to 6 weeks. Moreover, by combiningappropriate developers and couplers, it must be possible to create awide range of different color shades.

Attempts have already been made to improve the properties ofm-phenylenediamines by introduction of substituents. In this respect,the reader is referred to German Unexamined Patent Application DE-OS 3028 131 which, among other things, describes colorants containing ascouplers special m-phenylenediamines alkyl-substituted in the4-position.

The hitherto known colorants, however, do not fully meet allrequirements placed on colorants. Hence, a need continued to exist fornovel couplers capable of meeting the aforecited requirement to a majorextent.

We have now found that by use of 1,3-diamino-4-heteroarylbenzenederivatives of general formula (I) it is possible to achieve intense,stable blue color shades in addition to natural, purple or violet ones.

Hence, the object of the present invention is an agent for oxidativedyeing of keratin fibers, for example wool, furs, feathers or hair,particularly human hair, based on a developer/coupler combinationcontaining as the coupler at least one 1,3-diamino-4-heteroarylbenzenederivative of formula (I) or a physiologically tolerated salt thereof,

wherein

X1 denotes sulfur, oxygen, C—R3 or N—R2;

X2 denotes nitrogen or C—R4;

X3 denotes sulfur, nitrogen, oxygen, CR—5 or N—R2;

R1, R3, R4 and R5 can be equal or different and independently of eachother denote hydrogen, a halogen atom (fluorine, chlorine, bromine oriodine), a cyano group, a C₁-C₄-alkoxy group, a C₁-C₆-alkyl group, aC₁-C₄-alkylthioether group, a mercapto group, a nitro group, an aminogroup, a C₁-C₄-monoalkylamino group, a di(C₁-C₄)alkylamino group, adi(C₁-C₄-hydroxyalkyl)amino group, a C₁-C₄-hydroxyalkylamino group, atrifluoromethane group, a—C(O)CH₃ group, a—C(O)CF₃ group, an—Si(CH₃)₃group, a C₁-C₄-hydroxyalkyl group or a C₃-C₄-dihydroxyalkyl group;

R2 denotes hydrogen, a C₁-C₆-alkyl group, a C₂-C₄-hydroxyalkyl group, aphenyl group or an acetyl group;

wherein at least one and at the most two X1 to X3 groups denote C—R3, orC—R4 or C—R5, and at the most one of the X1 to X3 groups denotes sulfur,oxygen or N—R2.

Compounds of formula (I) are, for example:

1,3-diamino-4-(2-thiophenyl)benzene,1,3-diamino-4-(3-thiophenyl)benzene,1,3-diamino-4-(1-methyl-1H-2-pyrrolyl)benzene,1,3-diamino-4-(2-pyrrolyl)benzene, 1,3-diamino-4-(2-furyl)benzene,1,3-diamino-4-(2-thiazolyl)benzene,1,3-diamino-4-(1H-2-imidazolyl)benzene, 1,3-diamino-4-(3-furyl)benzene,1,3-diamino-4-(3-amino-2-thiophenyl)benzene,1,3-diamino-4-(3-chloro-2-thiophenyl)benzene,1,3-diamino-4-(3-methyl-2-thiophenyl)benzene,1,3-diamino-4-(3-nitro-2-thiophenyl)-benzene,1,3-diamino-4-(4-amino-2-thiophenyl)benzene,1,3-diamino-4-(4-chloro-2-thiophenyl)benzene,1,3-diamino-4-(4-methyl-2-thiophenyl)benzene,1,3-diamino-4-(4-nitro-2-thiophenyl)benzene,1,3-diamino-4-(5-amino-2-thiophenyl)benzene,1,3-diamino-4-(5-chloro-2-thiophenyl)benzene,1,3-diamino-4-(5-methyl-2-thiophenyl)benzene,1,3-diamino-4-(5-nitro-2-thiophenyl)benzene,1,3-diamino-(2-amino-3-thiophenyl)benzene,1,3-diamino-(2-chloro-3-thiophenyl)benzene,1,3-diamino-(2-methyl-3-thiophenyl)benzene,1,3-diamino-(2-nitro-3-thiophenyl)benzene,1,3-diamino-(4-amino-3-thiophenyl)benzene,1,3-diamino-(4-chloro-3-thiophenyl)benzene,1,3-diamino-(4-methyl-3-thiophenyl)benzene,1,3-diamino-(4-nitro-3-thiophenyl)benzene,1,3-diamino-(5-amino-3-thiophenyl)benzene,1,3-diamino-(5-chloro-3-thiophenyl)benzene,1,3-diamino-(5-methyl-3-thiophenyl)benzene and1,3-diamino-(5-nitro-3-thiophenyl)benzene.

Preferred compounds of formula (I) are those wherein (i) X1 or X3denotes sulfur, X2 denotes C—R4 and X3 denotes C—R5 or X1 denotes C—R3;or (ii) X1 or X3 stands for sulfur, X2 stands for C—R4 and X3 stands forC—R5 or X1 stands for C—R3, and at least two of the R1, R3, R4 and R5groups denote hydrogen.

Particularly preferred are the following 1,3-diamino-4-heteroarylbenzenederivatives: 1,3-diamino-4-(2-thiophenyl)benzene,1,3-diamino-4-(3-thiophenyl)benzene and the physiologically toleratedsalts thereof.

The compounds of formula (I) can be used as free bases or in the form oftheir physiologically tolerated salts with inorganic or organic acids,for example hydrochloric acid, sulfuric acid, phosphoric acid, aceticacid, propionic acid, lactic acid or citric acid.

The 1,3-diamino-4-heteroarylbenzene derivatives of formula (I) arecontained in the colorant of the invention in a total amount of about0.005 to 20 wt. %, an amount of about 0.01 to 5 wt. % and particularly0.1 to 2.5 wt. % being preferred.

Suitable developers are all developers known to be used for suchcolorants, for example 1,4-diaminobenzene (p-phenylenediamine),1,4-diamino-2-methylbenzene (p-toluylenediamine),1,4-diamino-2,6-dimethylbenzene, 1,4-diamino-3,5-diethylbenzene,1,4-diamino-2,5-dimethylbenzene, 1,4-diamino-2,3-dimethylbenzene,2-chloro-1,4-diaminobenzene, 1,4-diamino-2-(2-thiophenyl)benzene,1,4-diamino-2-(3-thiophenyl)benzene, 1,4-diamino-2-(3-pyridinyl)benzene,2,5-diaminobiphenyl, 1,4-diamino-2-methoxymethylbenzene,1,4-diamino-2-aminomethylbenzene, 1,4-diamino-2-hydroxymethylbenzene,1,4-diamino-2-(2-hydroxyethoxy)benzene, 1-(2,5-diaminophenyl)-ethanol,2-[2-(acetylamino)ethoxy]-1,4-diaminobenzene, 4-phenylaminoaniline,4-dimethylaminoaniline, 4-diethylaminoaniline, 4-dipropylaminoaniline,4-[ethyl-(2-hydroxyethyl)amino]aniline,4-[di(2-hydroxyethyl)amino]aniline,4-[di(2-hydroxyethyl)-amino]-2-methylaniline,4-[(2-methoxyethyl)amino]aniline, 4-[(3-hydroxypropyl)amino]-aniline,4-[(2,3-dihydroxypropyl)amino]aniline,1,4-diamino-2-(2-hydroxyethyl)benzene,1,4-diamino-2-(1-methylethyl)benzene,1,3-bis[(4-aminophenyl)(2-hydroxyethyl)amino]-2-propanol,1,4-bis[(4-amino-phenyl)amino]butane,1,8-bis(2,5-diaminophenoxy)-3,6-dioxaoctane, 4-aminophenol,4-amino-3-methylphenol, 4-amino-3-(hydroxymethyl)phenol,4-amino-3-fluorophenol, 4-methylaminophenol,4-amino-2-(aminomethyl)phenol, 4-amino-2-(hydroxymethyl)phenol,4-amino-2-fluorophenol, 4-amino-2-[(2-hydroxyethyl)amino]methylphenol,4-amino-2-methylphenol, 4-amino-2-methoxymethyl)phenol,4-amino-2-(2-hydroxyethyl)phenol, 5-aminosalicylic acid,2,5-diaminopyridine, 2,4,5,6-tetraaminopyrimidine,2,5,6-triamino-4-(1H)-pyrimidone,4,5-diamino-1-(2-hydroxyethyl)-1H-pyrazole,4,5-diamino-1-(1-methylethyl)-1H-pyrazole,4,5-diamino-1-[(4-methylphenyl)methyl]-1H-pyrazole,1-[(4-chlorophenyl)methyl]-4,5-diamino-1H-pyrazole,4,5-diamino-1-methyl-1H-pyrazole,4,5-diamino-3-methyl-1-methyl-1H-pyrazole, 2-aminophenol,2-amino-6-methylphenol and 2-amino-5-methylphenol.

The colorant of the invention can optionally also contain othercouplers, for example 2,6-diaminopyridine,2-amino-4-[(2-hydroxyethyl)amino]anisole,2,4-diamino-1-fluoro-5-methylbenzene,2,4-diamino-1-methoxy-5-methylbenzene,2,4-diamino-1-ethoxy-5-methylbenzene,2,4-diamino-1-(2-hydroxyethoxy)-5-methylbenzene,2,4-[(2-hydroxyethyl)amino]-1,5-dimethoxybenzene,2,3-diamino-6-methoxypyridine,3-amino-6-methoxy-2-(methylamino)pyridine,2,6-diamino-3,5-dimethoxypyridine, 3,5-diamino-2,6-dimethoxypyridine,1,3-diaminobenzene, 2,4-diamino-1-(2-hydroxyethoxy)benzene,2,4-diamino-1,5-di(2-hydroxyethoxy)benzene,1-(2-aminoethoxy)-2,4-diaminobenzene,2-amino-1-(2-hydroxyethoxy)-4-methylaminobenzene,2,4-diaminophenoxyacetic acid, 3-di[(2-hydroxyethyl)amino]aniline,4-amino-2-di[(2-hydroxyethyl)amino]-1-ethoxybenzene,5-methyl-2-(1-methylethyl)phenol, 3-[(2-hyd roxyethyl)amino]aniline,3-[(2-aminoethyl)amino]aniline, 1,3-di(2,4-diaminophenoxy)propane,1,3-di(2,4-diaminophenoxy)methane, 1,3-diamino-2,4-dimethoxybenzene,2,6-bis-(2-hydroxyethyl)aminotoluene, 4-hydroxyindole,3-dimethylaminophenol, 3-diethylaminophenol, 5-amino-2-methylphenol,5-amino-4-fluoro-2-methylphenol, 5-amino-4-methoxy-2-methylphenol,5-amino-4-ethoxy-2-methylphenol, 3-amino-2,4-dichlorophenol,5-amino-2,4-dichlorophenol, 3-amino-2-methylphenol,3-amino-2-chloro-6-methylphenol, 3-aminophenol,2-[(3-hydroxyphenyl)amino]acetamide,5-[(2-hydroxyethyl)amino]-2-methylphenol,3-[(2-hydroxyethyl)amino]phenol, 3-[(2-methoxyethyl)amino]phenol,5-amino-2-ethylphenol, 2-(4-amino-2-hydroxyphenoxy)ethanol,5-[(3-hydroxypropyl)amino]-2-methylphenol,3-[(2,3-dihydroxypropyl)amino]-2-methylphenol,3-[(2-hydroxyethyl)amino]-2-methylphenol, 2-amino-3-hydroxypyridine,5-amino-4-chloro-2-methylphenol, 1-naphthol, 1,5-dihydroxynaphthalene,1,7-dihydroxynaphthalene, 2,3-dihydroxynaphthalene,2,7-dihydroxynaphthalene, 2-methyl -1-naphthol acetate,1,3-dihydroxybenzene, 1-chloro-2,4-dihydroxynaphthalene,2-chloro-1,3-dihydroxybenzene,1,2-dichloro-3,5-dihydroxy-4-methylbenzene,1,5-dichloro-2,4-dihydroxybenzene, 1,3-dihydroxy-2-methylbenzene,3,4-methylenedioxyphenol, 3,4-methylenedioxyaniline,5-[(2-hydroxyethyl)amino]-1,3-benzodioxole,6-bromo-1-hydroxy-3,4-methylenedioxybenzene, 3,4-diaminobenzoic acid,3,4-dihydro-6-hydroxy-1,4(2H)benzoxazine,6-amino-3,4-dihydro-1,4(2H)benzoxazine, 3-methyl-1-phenyl-5-pyrazolone,5, 6-dihydroxyindole, 5, 6-dihydroxyindoline, 5-hydroxyindole,6-hydroxyindole, 7-hydroxyindole and 2,3-indolinedione.

The couplers and developers can be present in the colorant of theinvention either individually or in admixture with one another, thetotal amount of couplers and developers in the colorant of the inventioneach being about 0.005 to 20 wt. % preferably about 0.01 to 5.0 wt. %and particularly 0.1 to 2.5 wt. % (based on the total amount ofcolorant). The total amount of the developer-coupler combinationcontained in the colorant described herein is preferably about 0.01 to20 wt. %, an amount of about 0.02 to 10 wt. % and especially 0.2 to 6wt. % being particularly preferred. In general, the developer and thecoupler are used in approximately equimolar amounts; however, it is notdisadvantageous if the developer is present in a certain excess ordeficiency (for example in a coupler: developer ratio of 1:2 to 1:0.5).

Moreover, the colorant of the invention can also contain other dyecomponents, for example 6-amino-2-methylphenol and2-amino-5-methylphenol, as well as common anionic, cationic,zwitterionic or nonionic direct dyes, for example triphenylmethane dyessuch as 4-[(4′-aminophenyl)-(4′-imino-2″, 5″-cyclohexadien-1 ″-ylidene)methyl]-2-methylaminobenzene monohydrochloride (Color Index [C.I.] 42510) and4-[(4′-amino-3′-mthylphenyl)-(4″-imino-3″-methyl-2″,5″-cyclohexadien-1″-ylidene)methyl]-2-methylarninobenzene monohydrochloride (C.I. 42 520), aromaticnitro dyes such as 4-(2′-hydroxyethyl)aminonitrotoluene,2-amino-4,6-dinitrophenol, 2-amino-5-(2′-hydroxyethyl)aminonitrobenzene,2-chloro-6-(ethylamino)-4-nitrophenol,4-chloro-N-(2-hydroxyethyl-2-nitroaniline,5-chloro-2-hydroxy-4-nitroaniline, 2-amino-4-chloro-6-nitrophenol and1-(2′ureidoethyl)amino-4-nitrobenzene, azo dyes such as, for example,sodium 6-[(4′-aminophenyl)azo]-5-hydroxynaphthalene-1-sulfonate (C.I. 14805) and disperse dyes, for example 1,4-diaminoanthraquinone and1,4,5,8-tetraaminoanthraquinone. The colorants of the invention cancontain the aforesaid dye components in an amount from about 0.1 to 4wt. %.

The couplers and developers as well as the other dye components,provided they are bases, can, of course, also be used in the form oftheir physiologically tolerated salts with organic or inorganic acids,for example hydrochloric acid or sulfuric acid, or—if they containaromatic OH groups—in the form of their salts with bases, for example asalkali metal phenolates.

Moreover, if the colorants of the invention are to be used for coloringhair, they can contain other common cosmetic agents, for exampleantioxidants such as ascorbic acid, thioglycolic acid or sodium sulfite,as well as perfume oils, complexing agents, wetting agents, emulsifiers,thickeners and hair-care agents.

The colorant of the invention can be in the form of, for example, asolution, particularly an aqueous or aqueous-alcoholic solution. Aparticularly preferred formulation form, however, is a cream, gel oremulsion. Such a composition consists of a mixture of the dye componentsand the usual additives employed for such compositions.

Common additives to solutions, creams, emulsions or gels are, forexample solvents such as water, lower aliphatic alcohols, for exampleethanol, propanol or isopropanol, glycerol or glycols such as1,2-propylene glycol, moreover wetting agents or emulsifiers from theclasses of anionic, cationic, amphoteric or nonionic surface-activeagents, for example fatty alcohol sulfates, ethoxylated fatty alcoholsulfates, alkylsulfonates, alkylbenzenesulfonates,alkyltrimethylammonium salts, alkylbetaines, ethoxylated fatty alcohols,ethoxylated nonylphenols, fatty acid alkanolamides and ethoxylated fattyesters, furthermore thickeners such as the higher fatty alcohols,starch, cellulose derivatives, petrolatum, paraffin oil and fatty acids,also hair-care agents, such as cationic resins, lanolin derivatives,cholesterol, pantothenic acid and betaine. The cited constituents areused in amounts commonly employed for such purposes, for example thewetting agents and emulsifiers at a concentration of about 0.5 to 30 wt.%, the thickeners in an amount from about 0.1 to 25 wt. % and thehair-care agents at a concentration from about 0.1 to 5 wt. %.

Depending on the composition, the colorant of the invention can beweakly acidic, neutral or alkaline. In particular, it has a pH of about6.5 to 11.5. Adjustment to a basic pH is preferably done with ammonia,but it can also be done with an organic amine, for examplemonoethanolamine and triethanolamine, or with an inorganic base such assodium hydroxide and potassium hydroxide. Suitable for adjustment to anacidic pH are inorganic or organic acids, for example phosphoric acid,acetic acid, citric acid or tartaric acid.

For oxidative dyeing of hair, the afore-described colorants are mixedwith an oxidant just before use, and the resulting mixture is applied tohair in an amount sufficient for the hair-dyeing treatment, in generalabout 50 to 200 grams, depending on the hair fullness. The ready-to-useoxidation dye obtained by mixing with the oxidant preferably has a pH of6.5 to 11.5.

Suitable oxidants for developing the hair coloration are mainly hydrogenperoxide or its products of addition to urea, melamine, sodium borate orsodium carbonate, in the form of a 3-12%, preferably 6% aqueoussolution, atmospheric oxygen also being suitable. When a 6% hydrogenperoxide solution is used as oxidant, the weight ratio of hair colorantto oxidant is from 5:1 to 1:2, but preferably 1:1. Larger amounts ofoxidant are used primarily at higher dye concentrations in the haircolorant or when strong bleaching of the hair is wanted at the sametime. The mixture is allowed to act on the hair at 15 to 50° C. forabout 10 to 45 min, preferably 30 min, after which the hair is rinsedwith water and dried. Optionally, following this rinsing, the hair iswashed with a shampoo and optionally post-rinsed with a weak organicacid, for example citric acid or tartaric acid. The hair is then dried.

The colorants of the invention containing a1,3-diamino-4-heteroarylbenzenederivative of formula (I) as coupler givehair colorations of excellent color fastness, particularly in terms oflight fastness, wash fastness and rubbing fastness. As far as the dyeingproperties are concerned, the hair colorants of the invention, dependingon the kind and composition of the dye component, provide a wide rangeof different color shades from blond to brown, purple, violet and evenblue and black, depending on the developer-coupler combination. Theintense, stable blue color shades obtainable in this manner areparticularly noteworthy. In particular, the very good coloringproperties of the hair colorant of the present invention also manifestthemselves in that these colorants make it possible to dye graying hair,chemically not previously damaged, without any problems and with goodcovering power.

The 1,3-diamino-4-heteroarylbenzene derivatives of formula (I) can beprepared by known methods of synthesis, for example by methods similarto those described in the following examples.

The 1,3-diamino-4-heteroarylbenzene derivatives of formula (I) arereadily water-soluble and afford colorations, particularly in the bluerange of shades, with excellent color fastness, particularly in terms oflight fastness, wash fastness and rubbing fastness. Moreover, they haveoutstanding storage stability, particularly as constituents of thehereindescribed oxidation colorants.

Hence, another object of the present invention are1,3-diamino-4-heteroarylbenzene derivatives of general formula (I)wherein X2 is not nitrogen when X1 denotes sulfur.

The following examples illustrate the object of the invention in greaterdetail without limiting its scope.

EXAMPLES Example 1

A. Synthesis of tert.butyl(4-bromo-3-tert.butoxycarbonylaminophenyl)carbamate

A solution of 6.0 g (33.7 mmoles) of N-bromosuccinimide in 50 mL of1,2-dimethoxyethane was added dropwise to a suspension of 10 g (32.4mmoles) of tert.butyl (3-tert.butoxycarbonylaminophenyl)carbamate at 0°C. over a period of 2 hours. The reaction mixture was allowed to agitatefor an additional 2 hours. At the end of the reaction, the reactionmixture was poured into 300 mL of water, which produced a precipitate.The precipitate was filtered off and washed with water.

This gave 11 g (94% of the theoretical) of tert.butyl(4-bromo-3-tert.butoxycarbonylaminophenyl)carbamate.

¹H-NMR (300 MHz, DMSO-D6: δ=9.51 (s,1H), 8.43 (s, 1H), 7.89 (s, 1H),7.47 (d, 1H), 7.18 (d, 1H), 1.47 (d, 18H).

B. Synthesis of tert.butyl3-tert.butoxycarbonylamino-4-(4,4,5,5-tetramethyl-[1,3,2]dioxa-2-borolanyl)phenyl Carbamate

210 mL of degassed dioxane was added to a mixture of 7.8 g (20.2 mmoles)of tert.butyl (4-bromo-3-tert.butoxycarbonylaminophenyl)carbamate fromstep A, 12.8 g (50.6 mmoles) of4,4,4′,4′,5,5,5′,5′-octamethyl[2,2′]bis([1,3,2]dioxaborinanyl), 2 g (2.9mmoles) ofdichloro-[1,1′-bis(diphenylphospino)ferrocene]palladium[(PdCl₂(dppf)]and 6.2 g (63.2 mmoles) of potassium acetate under argon. The mixturewas allowed to agitate 26 h at 80° C., and to it was then added amixture of 4.2 g (16.9 mmoles) of diboronpinacole ester and 700 mg (0.95mmole) of PdCl₂ (dppf). The reaction mixture was allowed to agitate foran additional 14 h at 80° C., after which it was poured into water andthe resulting mixture was extracted with ethyl acetate. The organicphase was then washed with saturated aqueous sodium chloride solution,dried over sodium sulfate, filtered and the filtrate evaporated todryness. The resulting crude product was purified on deactivatedsilicate gel with hexane/ethyl acetate (1:1). This gave 6.20 g (71% ofthe theoretical) of tert.butyl3-tert.butoxycarbonylamino-4-(4,4,5,5-tetramethyl[1,3,2]dioxa-2-borolanyl)phenylcarbamate.

C. Synthesis of 4-heteroaryl-1,3-diaminobenzenes

0.09 g (0.0002 mole) of tert.butyl3-tert.butoxycarbonylamino-4-(4,4,5,5-tetramethyl[,3,2]dioxa-2-borolanyl)phenylcarbamate from step B and 0.0004 mole of the appropriate bromoderivative were dissolved in 10 mL of 1,2-dimethoxyethane. Then, 0.01 g(0.000005 mole) of tetrakis-(triphenylphosphine)palladiumand 0.26 mL of2N potassium carbonate solution were added, and the reaction mixture washeated to 80° C. At the end of the reaction, the reaction mixture waspoured into 10 mL of ethyl acetate and the organic phase was extractedwith dilute sodium hydroxide solution and then dried over magnesiumsulfate. The solvent was distilled off in a rotary evaporator, and theresidue was purified on silica gel with petroleum ether/ethyl acetate(9:1). The product thus obtained was dissolved in 4 mL of ethanol andheated to 50° C. To prepare the hydrochloride, 1.5 mL of a 2.9 molarethanolic solution of hydrochloric acid was added dropwise. Theprecipitate was filtered off, washed twice with 1-mL portions of ethanoland then dried.

a) 1,3-Diamino-4-(2-thiophenyl)benzene Hydrochloride

Bromo derivative used: 2-bromothiophene

Mass spectrum: MH+191(50)

b) 1,3-Diamino-4-(3-methyl-2-thiophenyl)benzene Hydrochloride

Bromo derivative used: 2-bromo-3-methylthiophene

Mass spectrum: MH+205(80)

c) 1,3-Diamino-4-(5-nitro-2-thiophenyl)benzene Hydrochloride

Bromo derivative used: 2-bromo-5-nitrothiophene

Mass spectrum: MH+236(100)

d) 1,3-Diamino-4-(2-thiazolyl)benzene

Bromo derivative used: 2-bromothiazole

Mass spectrum: MH+192(100)

Examples 2 to 5 Hair Colorants

Hair colorant solutions having the following composition were prepared:

1.25 mmoles of coupler of formula (I) according to Table 1 1.25 mmolesof developer according to Table 1 1.0 g of potassium oleate (8% aqueoussolution) 1.0 g of ammonia (22% aqueous solution) 1.0 g of ethanol 0.3 gof ascorbic acid to 100.0 g water

Just before use, 50 g of the foregoing coloring solution was mixed with50 g of a 6% aqueous hydrogen peroxide solution. The mixture was thenapplied to bleached hair. After an exposure time of 30 min at 40° C.,the hair was rinsed with water, washed with a commercial shampoo anddried. The resulting color shades are presented in Table 1.

TABLE 1 Developer* III IV II 2,5-di- 4,5-diamino- I 2,5-di- amino-1-(2′-hy- Ex- Coupler of 1,4-di- amino- phenyl- droxyethyl)- ampleFormula(I) amino- toluene ethanol pyrazole No. as per benzene sulfatesulfate sulfate 2. Example 1a dark-blue dark-blue dark-blue purple 3.Example 1b dark-blue dark-blue dark-blue purple 4. Example 1c dark-bluedark-blue dark-blue purple 5. Example 1d gray light-gray light-graylight-gray *The original reads “Coupler” - an abvious error - Translator

Examples 6 to 11 Hair Colorants

Hair colorant solutions of the following composition were prepared:

X g of 1,3-diamino-4-heteroarylbenzene (coupler K1 of formula (I) as perTable 4) U g of developer E8 to E15 as per Table 2 Y g of coupler K11 toK36 as per Table 4 Z g of direct dye D1 to D3 as per Table 3 10.0 g ofpotassium oleate (8% aqueous solution) 10.0 g of ammonia (22% aqueoussolution) 10.0 g of ethanol 0.3 g of ascorbic acid to 100.0 g water

Just before use, 30 g of the foregoing coloring solution was mixed with30 g of a 6% aqueous solution of hydrogen peroxide. The mixture was thenapplied to bleached hair. After an exposure time of 30 min at 40° C.,the hair was rinsed with water, washed with a commercial shampoo anddried. The coloring results are presented in Table 5.

TABLE 2 Developers E8 1,4-diaminobenzene E9 2,5-diaminophenylethanolsulfate E10 3-methyl-4-aminophenol E11 4-amino-2-aminomethylphenoldihydrochloride E12 4-aminophenol E13N,N-bis(2′-hydroxyethyl)-p-phenylenediamine sulfate E144,5-diamino-1-(2′-hydroxyethyl)pyrazole sulfate E15 2,5-diaminotoluenesulfate

TABLE 3 Direct Dyes D1 2,6-diamino-3-[(3-pyridinyl)azo]pyridine D26-chloro-2-ethylamino-4-nitrophenol D3 2-amino-6-chloro-4-nitrophenol

TABLE 4 Couplers K1 1,3-diamino-4-(2-thiophenyl)benzene hydrochlorideK11 1,3-diaminobenzene K12 2-amino-4-(2′-hydroxyethyl)aminoanisolesulfate K13 1,3-diamino-4-(2′-hydroxyethoxy)benzene sulfate K142,4-diamino-5-fluorotoluene sulfate K153-amino-2-methylamino-6-methoxypyridine K163,5-diamino-2,6-dimethoxypyridine dihydrochloride K172,4-diamino-5-ethoxytoluene sulfate K18 N-(3-dimethylamino)phenylureaK19 1,3-bis(2,4-diaminophenoxy)propane tetrahydrochloride K213-aminophenol K22 5-amino-2-methylphenol K233-amino-2-chloro-6-methylphenol K24 5-amino-4-fluoro-2-methylphenolsulfate K25 1-naphthol K26 1-acetoxy-2-methylnaphthalene K311,3-dihydroxybenzene K32 2-methyl-1,3-dihydroxybenzene K331-chloro-2,4-dihydroxybenzene K344-(2′-hydroxyethyl)amino-1,2-methylenedioxybenzene.HCl K353,4-methylenedioxyphenol K36 2-amino-5-methylphenol

TABLE 5 Hair Colorants Example No. 6 7 8 9 10 11 Dyes (Amount of dye ingrams) K1 0.1  0.12 0.05 0.07 0.10 0.12 E8 0.30 E9 0.25 0.3  E15 0.250.3  0.25 K12 0.05 K13 0.05 K31 0.20 0.15 0.20 0.10 K32 0.20 0.10 0.10K33 0.20 K21 0.05 K22 0.05 K23 0.05 0.10 0.10 0.10 Coloring blond blondblond blond blond blond result

Examples 13 to 17 Hair Colorants

Dye carriers in cream form and having the following composition wereprepared:

X g of 1,3-diamino-4-heteroarylbenzene (coupler K1 of formula (I) as perTable 4) U g of developer E8 to E15 as per Table 2 Y g of coupler K11 toK36 as per Table 4 Z g of direct dye D2 as per Table 3 15.0 g of cetylalcohol 0.3 g of ascorbic acid 3.5 g of sodium lauryl alcohol diethyleneglycol ether sulfate, 28% aqueous solution 3.0 g of ammonia, 22% aqueoussolution 0.3 g of sodium sulfite, anhydrous to 100 g water

Just before use, 30 g of the foregoing coloring cream was mixed with 30g of a 6% aqueous solution of hydrogen peroxide. The mixture was thenapplied to the hair. After an exposure time of 30 min at 40° C., thehair was rinsed with water, washed with a commercial shampoo and dried.The coloring results are shown in Table 6.

TABLE 6 Hair Colorants Example No. 12 13 14 15 16 17 Dyes (Amount of dyein grams) K1 0.6 1.3 1.15 0.15 0.15 0.15 E8 1.5 E13 1.6 0.7  E15 1.8 0.7  0.7  K12 0.6 K31  1.10  1.10 1.10 0.40 0.40 0.40 K23 0.05 0.10 0.100.10 D2 0.10 0.10 0.10 Coloring black black black brown brown brownresults

Unless otherwise indicated, all percentages in the present applicationare by weight.

What is claimed is:
 1. Agent for oxidative dyeing of keratin fiberscontaining a combination of at least one coupler and at least onedeveloper, wherein said at least one coupler comprises at least one1,3-diamino-4-heteroarylbenzene derivative of formula (I) or aphysiologically tolerated salt thereof,

wherein X1 denotes sulfur, oxygen, C—R3 or N—R2; X2 denotes nitrogen orC—R4; X3 denotes sulfur, nitrogen, oxygen, C—R5 or N—R2; R1, R3, R4 andR5 can be equal or different and independently of each other denotehydrogen, a halogen atom, a cyano group, a C₁-C₄-alkoxy group, aC₁-C₆-alkyl group, a C₁-C₄-alkylthioether group, a mercapto group, anitro group, an amino group, a C₁-C₄-monoalkylamino group, adi(C₁-C₄)-alkylamino group, a di(C₁-C₄-hydroxyalkyl)amino group, aC₁-C₄-hydroxyalkylamino group, trifluoromethane group, a —C(O)CH₃ group,a —C(O)CF₃ group, an —Si(CH₃)₃ group, a C₁-C₄-hydroxyalkyl group or aC₃-C₄-dihydroxyalkyl group; R2 denotes hydrogen, a C₁-C₆-alkyl group, aC₂-C₄-hydroxyalkyl group, a phenyl group or an acetyl group; wherein atleast one and at the most two X1 to X3 groups denote C—R3, or C—R4 orC—R5, and at the most one of the X1 to X3 groups denotes sulfur, oxygenor N—R2.
 2. Agent according to claim 1, wherein X1 or X3 denotes sulfur,X2 denotes C—R4 and X3 denotes C—R5 or X1 denotes C—R3.
 3. Agentaccording to claim 1, wherein X1 or X3 denote sulfur, X2 denotes C—R4and X3 denotes C—R5 or X1 denotes C—R3, and at least two of the R1, R3,R4 and R5 groups are hydrogen.
 4. Agent according to claim 1, wherein atat least one 1,3-diamino-4-heteroarylbenzene derivative of formula (I)is selected from the group consisting of1,3-diamino-4-(2-thiophenyl)benzene, 1,3-diamino-4-(3-thiopheny)benzeneand the physiologically tolerated salts thereof.
 5. Agent according toclaim 1, containing the at least one 1,3-diamino-4-heteroarylbenzene offormula (I) in an amount from 0.005 to 20 wt. %.
 6. Agent according toclaim 1, having a pH from 6.5 to 11.5.
 7. Agent according to claim 1,wherein the at least one developer is selected from the group consistingof 1,4-diaminobenzene, 1,4-diamino-2-methylbenzene,1,4-diamino-2,6-dimethylbenzene, 1,4-diamino-3,5-diethylbenzene,1,4-diamino-2,5-dimethylbenzene, 1,4-diamino-2,3-dimethylbenzene,2-chloro-1,4-diaminobenzene, 1,4-diamino-2-(2-thio-phenyl)-benzene,1,4-diamino-2-(3-thio-phenyl)benzene,1,4-diamino-2-(3-pyridinyl)-benzene, 2,5-diaminobiphenyl,1,4-diamino-2-methoxymethylbenzene, 1,4-diamino-2-aminomethylbenzene,1,4-diamino-2-hydroxymethylbenzene,1,4-diamino-2-(2-hydroxyethoxy)benzene, 1-(2,5-diaminophenyl)-ethanol,2-[2-(acetylamino)ethoxy]-1,4-diamino-benzene, 4-phenyl-amino-aniline,4-dimethylamino-aniline, 4-diethylaminoaniline, 4-dipropylaminoaniline,4-[ethyl-(2-hydroxyethyl)amino]aniline,4-[di(2-hydroxyethyl)amino]aniline,4-[di(2-hydroxyethyl)amino]-2-methylaniline,4-[(2-methoxyethyl)amino]aniline, 4-[(3-hydroxypropyl)amino]-aniline,4-[(2,3-dihydroxypropyl)amino]aniline,1,4-diamino-2-(2-hydroxyethyl)-benzene,1,4-diamino-2-(1-methylethyl)benzene,1,3-bis-[(4-aminophenyl)-(2-hydroxyethyl)amino]-2-propanol,1,4-bis-[(4-aminophenyl)-amino]butane,1,8-bis(2,5-diaminophenoxy)-3,6-dioxaoctane, 4-amino-phenol,4-amino-3-methylphenol, 4-amino-3-(hydroxymethyl)phenol,4-amino-3-fluorophenol, 4-methyl-aminophenol,4-amino-2-(aminomethyl)phenol, 4-amino-2-(hydroxymethyl)phenol,4-amino-2-fluorophenol, 4-amino-2-[(2-hydroxyethyl)amino]-methylphenol,4-amino-2-methylphenol, 4-amino-2-(methoxymethyl)phenol,4-amino-2-(2-hydroxyethyl)phenol, 5-aminosalicylic acid,2,5-diaminopyridine, 2,4,5,6-tetraaminopyrimidine,2,5,6-triamino-4-(1H)-pyrimidone,4,5-diamino-1-(2-hydroxyethyl)-1H-pyrazole,4,5-diamino-1-(1-methylethyl)-1H-pyrazole,4,5-diamino-1-[(4-methylphenyl)-methyl]-1H-pyrazole,1-[(4-chlorophenyl)methyl]-4,5-diamino-1H-pyrazole,4,5-diamino-1-methyl-1H-pyrazole,4,5-diamino-3-methyl-1-methyl-1H-pyrazole, 2-aminophenol,2-amino-6-methylphenol and 2-amino-5-methyl-phenol.
 8. Agent accordingto claim 1, wherein the at least one developer and the at least onecoupler are each present in a total amount of 0.005 to 20 wt/%.
 9. Agentaccording to claim 1, further comprising at least one direct dye. 10.Agent according to claim 1, consisting of a hair colorant.
 11. A1,3-diamino-4-heteroarylbenzene derivative at formula (I)

wherein X1 denotes sulfur, oxygen, C—R3 or N—R2; X2 denotes nitrogen orC—R4; X3 denotes sulfur, nitrogen, oxygen, C—R5 or N—R2; R1, R3, R4 andR5 can be equal or different and, independently of each other, denotehydrogen, a halogen atom, a cyano group, a C₁-C₄-alkoxy group, aC₁-C₆-alkyl group, a C₁-C₄-alkylthloether group, a mercapto group, anitro group, an amino group, a C₁-C₄-monoalkylamino group, adi(C₁-C₄)alkylamino group, a di(C₁-C₄-hydroxyalkyl)amino group, aC₁-C₄-hydroxyalkylamino group, a trifluoromethane group, a —C(O)CH₃group, a —C(O)CF₃ group, an —Sl(CH₃)₃ group, a C₁-C₄-hydroxyalkyl groupor a C₃-C₄-dihydroxyalkyl group; R2 denotes hydrogen, a C₁-C₆-alkylgroup, a C₂-C₄-hydroxyalkyl group, a phenyl group or an acetyl group;wherein at least one and at the most two X1 to X3 groups denote C—R3,C—R4 or C—R5, and at the most one of the X1 to X3 groups denotes sulfur,oxygen or N—R2, with the proviso that X2 does not stand for nitrogenwhen X1 stands for sulfur.